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/** \file     UnitPartitioner.h
 *  \brief    Provides a class for partitioning management
 */

#pragma once

#include "Unit.h"

#include "CommonDef.h"

namespace vvdec
{

typedef UnitArea* Partitioning;

//////////////////////////////////////////////////////////////////////////
// PartManager class - manages the partitioning tree
//
// contains the currently processed partitioning area (currArea)
// as well as the all partitioning decisions that led to this area
// being processed (in m_partStack).
//////////////////////////////////////////////////////////////////////////

enum PartSplit
{
  CTU_LEVEL        = 0,
  CU_QUAD_SPLIT,
  CU_HORZ_SPLIT,
  CU_VERT_SPLIT,
  CU_TRIH_SPLIT,
  CU_TRIV_SPLIT,
  TU_MAX_TR_SPLIT,
  TU_NO_ISP,
  TU_1D_HORZ_SPLIT,
  TU_1D_VERT_SPLIT,
  SBT_VER_HALF_POS0_SPLIT,
  SBT_VER_HALF_POS1_SPLIT,
  SBT_HOR_HALF_POS0_SPLIT,
  SBT_HOR_HALF_POS1_SPLIT,
  SBT_VER_QUAD_POS0_SPLIT,
  SBT_VER_QUAD_POS1_SPLIT,
  SBT_HOR_QUAD_POS0_SPLIT,
  SBT_HOR_QUAD_POS1_SPLIT,
  NUM_PART_SPLIT,
  CU_DONT_SPLIT           = 2000  ///< dummy element to indicate no splitting
};



struct PartLevel
{
  PartSplit         split;
  Partitioning      parts;
  unsigned          numParts;
  unsigned          idx;
  const CodingUnit *cuAbove;
  const CodingUnit *cuLeft;
  ModeType          modeType;
  bool              qgEnable;
  bool              qgChromaEnable;

  PartLevel();
  PartLevel( const PartSplit _split, const Partitioning _parts );

  void init();
};

// set depending on max QT / BT possibilities
typedef static_vector<PartLevel, 2 * MAX_CU_DEPTH + 1> PartitioningStack;

class Partitioner
{
protected:
  PartitioningStack m_partStack;
#if _DEBUG
  UnitArea          m_currArea;
#endif
  static const size_t partBufSize = 128;
  UnitArea          m_partBuf[partBufSize];
  ptrdiff_t         m_partBufIdx;

public:

  bool     isDualITree;
  unsigned maxBTD;
  unsigned maxBtSize;
  unsigned minBtSize;
  unsigned maxTtSize;
  unsigned minTtSize;
  unsigned maxTrSize;
  unsigned minQtSize;

  unsigned currDepth;
  unsigned currQtDepth;
  unsigned currTrDepth;
  unsigned currSubdiv;
  unsigned currMtDepth;
  unsigned currSliceIdx;
  unsigned currTileIdx;
  Position currQgPos;
  Position currQgChromaPos;

  unsigned currImplicitBtDepth;
  ChannelType chType;
  TreeType treeType;
  ModeType modeType;

  const Slice* slice;

  const PartLevel& currPartLevel          () const { return m_partStack.back(); }
  const UnitArea&  currArea               () const { return currPartLevel().parts[currPartIdx()]; }
        unsigned   currPartIdx            () const { return currPartLevel().idx; }
  const PartitioningStack& getPartStack   () const { return m_partStack; }
  const bool currQgEnable                 () const { return currPartLevel().qgEnable; }
  const bool currQgChromaEnable           () const { return currPartLevel().qgChromaEnable; }

  SplitSeries getSplitSeries              () const;

  void initCtu                            ( const UnitArea& ctuArea, const ChannelType _chType, const CodingStructure& cs, const Slice& slice );
  void splitCurrArea                      ( const PartSplit split, const CodingStructure &cs );
  void exitCurrSplit                      ( const CodingStructure& cs );
  bool nextPart                           ( const CodingStructure &cs, bool autoPop = false );
  bool hasNextPart                        () const;
  void setCUData                          ( CodingUnit& cu );
  void canSplit                           ( const CodingStructure &cs, bool& canNo, bool& canQt, bool& canBh, bool& canBv, bool& canTh, bool& canTv ) const;
  bool canSplit                           ( const PartSplit split, const CodingStructure &cs, bool isISP = false ) const;
  bool isSepTree                          ( const CodingStructure &cs ) const;
  bool isConsInter                        () const { return modeType == MODE_TYPE_INTER; }
  bool isConsIntra                        () const { return modeType == MODE_TYPE_INTRA; }
  void updateNeighbors                    ( const CodingStructure& cs );
};

//////////////////////////////////////////////////////////////////////////
// Partitioner namespace - contains methods calculating the actual splits
//////////////////////////////////////////////////////////////////////////

namespace PartitionerImpl
{
  int getCUSubPartitions     ( const UnitArea &area, const CodingStructure &cs, const PartSplit splitType, Partitioning& dst );
  int getMaxTuTiling         ( const UnitArea &area, const CodingStructure &cs,                            Partitioning& dst );
  int getTUIntraSubPartitions( const UnitArea &area, const CodingStructure &cs, const bool isDualITree,    const PartSplit splitType, Partitioning &sub, const TreeType treeType );
  int getSbtTuTiling         ( const UnitArea &area, const CodingStructure &cs, const PartSplit splitType, Partitioning& dst );
}

}
